The on-going deregulation in worldwide energy distribution markets is driving the need for smart utility distribution grids and smart meters, enabling both utility providers and consumers to monitor the detailed consumption of an end user at any time through open communication networks. The energy market is particularly concerned as of today but related issues are also relevant to other utility markets such as water or gas.
While a number of legacy meters already implement some point-to-point Automated Metering Reading (AMR) protocols using for instance standard optical or modem interfaces, they are not able to interact with either the end user home area network devices or the remote utility monitoring facilities using wireless or power line communication networks. The industry answer to this regulatory requirement in the next decade will therefore consist in swapping the legacy meters for so-called smart meters.
Smart meters enable utility providers to monitor the detailed consumption of an end user at any time through open communication networks. The consumption measurement sampling granularity can then be much finer than in legacy systems where the meters were manually controlled about once a year. It is also possible to support multiple tariffs from different providers and adapt them much more frequently in accordance with the finer measurement periods.
From the utility provider perspective, as there will be no more local measurement and physical control of the meter functionality by authorized personnel, the smart metering architecture needs careful design to ensure secure, tamper resistant and trusted data collection and transmission from the smart meters to the provider utility services facility. Various solutions can be defined based on state of the art cryptography protocols and a key management system under the control of the utility provider. Those solutions typically require the smart meter to generate its measurement reporting messages specifically for a given utility provider. In a deregulated market where the smart meter is able to negotiate its tariffs with multiple providers, this results in increased bandwidth and processing needs as well as tamper resistant design complexity, manufacturing costs and maintenance costs for the utility meters.
The document US 2008/0068213 discloses automatic meter reading systems for receiving standard consumption messages from encoder-receiver-transmitter devices located at the end user. To this end, these devices communicate with reading systems that periodically collect reading of residential gas, electric or water meters by using RF communications. Each encoder-receiver-transmitter device is uniquely identifiable so that its information can be properly associated with the corresponding customer account for billing purposes. The encoder-receiver-transmitter devices operates in a low-power standby mode during a majority of the time and it is provided with a timer which operates to periodically wake up the device so that it enters into an active operating mode.
The document U.S. Pat. No. 5,974,369 discloses an energy management system, in particular a recording node for receiving energy-related consumption meter data for calculating consumption amount and consumption rate for a particular time interval and for storing such information. Price data may be received at the recording node from an external source, e.g. over a network, such as a distributed network, which network may include the recording node. Pricing information might be updated any time a price change is implemented or projected. Service provider can receive previously accumulated consumption values and associated prices for past consumption intervals, for billing purposes over network. Data calculated by the recording node is available for reading by any authorized nodes on network or by other authorized external devices.
However, while keeping in mind that reporting data refers simultaneously to millions of utility meters, none of these documents suggests means for optimizing as far as possible the management of exchanged data in order to save bandwidth and computing resources. Besides, these documents merely suggest exchanging communications through a known network without taking care to prevent hacking and tampering caused by certain malicious persons.
From a security point of view, it is difficult to implement a powerful system for exchanging data, metered by a huge quantity of utility meters, which is fully tamper-proof against hackers. For instance, it is not reliable to implement a single cryptography system for reporting all utility meters given that such a system would require, for all these meters, a shared key that would be difficult to keep secret. As taught by the prior art, it is much easier to implement a security system by using physical access controls in order to monitor sensitive devices, for instance by installing locked gates and video monitoring cameras.
There is therefore a need for a more flexible smart metering network topology to optimize the smart metering operations, communications, and security.